Monday, 17 December 2012

Dangerous Things Done in Desperation.

With the seriousness of the situation regards AGW becoming more clear, talk of geo-engineering has increased. I think that rather than try to stem population increase, examine our economic system and expectations, and reduce CO2 emissions, this will be seen as a viable option in the years to come.

However geo-engineering will, I am confident, be used as an excuse to carry on emitting CO2 and avoiding dealing with the fundamental flaw in our civilisation; exponential growth in a finite world. It is dangerous and is a recipe for disaster.

I've recently been blogging about a new pattern of circulation in the Northern Hemisphere that has brought cool wet summers to the UK since 2007. This pattern has also been spotted by scientists who have recently published their findings. Edward Hanna seems to be mainly a Greenland specialist, but James Overland, Jennifer Francis, and Muyin Wang are, by their publication record, some of the leading experts in the study of the Arctic atmosphere. The pattern has been active in summers since 2007, yet it took until 2012 before the scientists published about it. Crucially, I can find no evidence of this pattern being found in GCM modelling studies, the authors of the study examining new pattern of atmospheric circulation do not refer to such a modelling study. Indeed there is one mention of models in the paper: "Coarse scale climate models may not be up to the task of resolving such connections."

So the best guess of three of the top experts in the Arctic atmosphere is that changes in the snowline are driving the process. It's an educated guess, they may be correct, and my citing this example is in no way a criticism of their abilities. However faced with an unexpected change it can take years to identify the change amongst the variability of weather, then more years to identify what processes are driving the change, if more than one hypothesis is available it can take years more to sort out what's really going on and which hypothesis is correct.

Let's suppose that a method of geo-engineering has been implemented, and that it then becomes noted that damaging weather is being experienced in one or more regions. It's already taken years of damaging weather to identify the pattern out of the noise of natural variability, years more to elucidate the most likely cause. How long does it take then to decide how to modify the geo-engineering to deal with the problem it has caused? And what further problems will that cause?

During these years populations are being subjected to flooding, drought, or storms, causing human suffering that was deliberately caused by the geo-engineering scheme. That is in contrast to AGW which proceeds as an unintended consequence of human actions, actions not intended to impact the climate system. What would a moral philosopher have to say about this, more to the point; what would a lawyer advising a group action on behalf of those affected have to say about this?

However these issues aren't what really scares me about geo-engineering.

In my recent post Something Wicked This Way Comes I wrote a paragraph trying to sum up the changes we're seeing now, with about 0.8degC warming, and asked what this means for the future: How bad is it going to get if this is just the start? Now imagine that we've decided to go with geo-engineering to deal with dangerous climate change.

There are three broad groups of techniques available:

Solar Radiation Management.

Carbon Dioxide Removal

Heat Transport

Heat Transport is probably the most dangerous with regards the risk of re-running the Paleocene Eocene Thermal Maximum (PETM). Burying heat in the deeps of the oceans will increase the temperatures of ocean shelves eventually, and whilst focus seems to be on Arctic methane the PETM and End Permian almost certainly involved methane hydrate destabilisation from lower latitudes. I'd go so far as to say that with what we know of the PETM and the End Permian, deliberately and actively burying heat in the oceans would be such mindless idiocy that its execution should earn the entire human race a Darwin Award.

Carbon Dioxide Removal would be costly. At current emissions of about 33,000,000,000 tons of CO2 per year any method to extract CO2 would be costly, in land use, fuel, money, or all of those. Wikipedia lists four candidate options.

Bio-energy with carbon capture and storage to remove carbon and simultaneously provide energy

Carbon air capture to remove carbon dioxide from ambient air

Ocean nourishment including iron fertilisation of the oceans

All of which have land use or energy input requirements. Clearing more land would place more pressure upon ecosystems, or food prices. Any energy used would have to be non fossil fuel, which would eat into whatever offsets could be made to fossil fuel burning reductions. Overall the whole process would have to not impact the poor (food prices), and would have to be substantial.

This leaves Solar Radiation Management (SRM). Firstly this fails to address ocean acidification, and leaves atmospheric CO2 accumulating. Painting the roofs of whole cities pale colours could induce the sort of climatic effects that have lead to the new circulation pattern, or cold boreal winters, more here. These would likely be highly unpredictable, only fine resolution models would stand a chance of capturing the impacts. Space based solutions are fantasy at present, if used we need to be able to maintain them for millennia. Perhaps the cheapest option would be adding additives to jet aircraft fuels and ship fuels, but again we'd need to keep it up for millennia. (And if any tin foil hatters post about chemtrails and the NWO they'll be deleted without warning.)

Why do I say we would need to keep up SRM for millennia?

Archer & Brovkin's 2006 paper "The Millennial Atmospheric Lifetime of Anthropogenic CO2", PDF, shows that the emissions of CO2 will remain in the atmosphere/ocean system for thousands of years. Their abstract sums up their findings perfectly:

The notion is pervasive in the climate science community and in the public at large that the climate impacts of fossil fuel CO2 release will only persist for a few centuries. This conclusion has no basis in theory or models of the atmosphere/ocean carbon cycle, which we review here. The largest fraction of the CO2 recovery will take place on time scales of centuries, as CO2 invades the ocean, but a significant fraction of the fossil fuel CO2, ranging in published models in the literature from 20–60%, remains airborne for a thousand years or longer. Ultimate recovery takes place on time scales of hundreds of thousands of years, a geologic longevity typically associated in public perceptions with nuclear waste.

So if we take any geo-engineering scheme that doesn't involve massive emissions reductions or active draw-down of CO2, we need to keep it up for at least 1000 years, the more CO2 we emit the longer the recovery of CO2 back to pre-industrial will take.

And if we falter...

Let's suppose we take the cheapest option available and decide on SRM, jet aircraft have additives added to fuel. We're shipping more over the Arctic routes during the summer when insolation matters, so we do the same for their fuel. We're successful, we manage to keep temperatures as they are now, maybe even knock a degree off Arctic temperatures. Leaving aside the effect of increasing ice on shipping (having been won over, we start dedicated flights). With each year that we're successful, CO2 builds in the atmosphere, the potential warming builds. Like a person in debt switching credit cards, we delay the inevitable. Just as the Credit Crunch caused so many people to default after years juggling the debt they'd accrued in pursuit of an unsustainable lifestyle: Should we falter we could face decades of accrued warming. But crucially, instead of hitting the planet at the rate happening at present, admittedly fast in geological terms, this warming could hit within years or a decade. Global temperatures have been rising steadily since about 1975, now imagine compressing that, and possibly more, into a decade. That prospect scares me more than just letting the process continued unchecked. Indeed, I'd go so far as to say that one couldn't deliberately devise a better way to unleash a climatic disaster.

I'm not saying we shouldn't try carbon sequestration, but it cannot be at the expense of food, the world's poor already have problems enough getting sufficient food. So before you lecture me about the benefits of biochar, or some other pet scheme to capture carbon, remember....

14 comments:

Brian
said...

I know that ocean acidification is clearly bad for ocean life, however, it appears to be one of the few substantial negative CO2 feedbacks. Coral reefs and their ilk undo an equal amount of geological weathering for every CO2 they deposit in limestone. The best estimation I could find on the web was that it was 1/50 the amount of CO2 as was released by humans, which was written in 2007, so 5000 years of a dead ocean and the CO2 is all cleaned up. I know that I am probably completely wrong, but are there any articles about this negative feedback loop?

Coral deposit limestone and in doing so take CO2 from the ocean, which in turn draws from the atmosphere as the ocean & atmosphere are interchangeable reservoirs.

So acidification killing coral reduces their CO2 sequestration. I doubt if it's a big factor due to the limited geographical spread of coral. On the flip side of the coin CO2 makes rain more acidic so increases weathering of rock, this again draws CO2 from the atmosphere, but it's a slow process.

An atom of calcium in seawater solution as the bicarbonate neutralizes two CO2s. When the carbonate is formed, one of those CO2s is no longer neutralized, and so coral formation reduces the CO2 carrying capacity of the ocean. It is thought that recovery from high atmospheric CO2 events occurs as the carbonate compensation depth rises and calcareous oozes dissolve into bicarbonates and ultimately pull CO2 from the atmosphere.

Bicarbonate is an cation HCO3- with an extra electron and must be paired with an anion with a missing electron, in this case Ca++. The calcium ion is missing two electrons and can thus pair with two bicarbonates.

Corals do in fact remove calcium from solution and thus increase ocean acidity by precipitating CaCO3 by the equation above. Brian's point was that killing the corals would stop this irresponsible behavior and thus help restore ocean alkalinity.

It really is the chemistry of reefs and ocean dwellers with calcium carbonate shells. They are CO2 sources and you can read about it here: http://www.climateshifts.org/?p=111. The same article has the what I consider shockingly high number of 1/50 anthro CO2 quote. I ran into the article when I was pondering all the hyperbole I have seen elsewhere of the oceans dying and reefs going extinct and how if they are right it might not be such a bad thing in the long run. I was just hoping someone could fillet my mental red herring.

Relating to your article, I think that you are right in regards to a complete warming suppression scheme, we would need a civilization that lasts tens of millennia. This is something humans have yet been able to accomplish. Or imagine a geoengineering war escalating from unseen consequences of one country's try at geoengineering? While I think it unlikely fantasy, maybe Ray Kurzwell's singularity would be necessary so we could migrate to a silicon platform where heat is less of an issue for our sentient survival. It seems like a much more energy sensible thing if we can accomplish it than trying to put the CO2 genie back in the bottle if we don't stop emitting in the near future.

Check out The Idiot Tracker in the blog list on the right hand side. He's made the case that geoengineering might not have to continue for millennia.http://theidiottracker.blogspot.co.uk/2012/12/does-geoengineering-have-to-continue.html

Thanks for the heads up. I actually used to think that just planting more forests was the answer, which is how I learned about a year ago through a circuitous route that reefs emit CO2. Strange how life comes full circle sometimes.

this was new and surprising to me as well - that reef carbonate formation is a source of CO2. But once asserted, a simple google search turns up pre-political scientific literature that confirms just that. For example

http://link.springer.com/content/pdf/10.1007%2FBF00255465

(pdf), from 1991. Note however the magnitude : 0.4 to 1.4 % of the then human emissions. I. e. not a large scale factor.